APHIS Lists of Proven Hosts of and Plants Associated with

Phytophthora ramorum

September 2022

Proven Host Plants of Phytophthora ramorum

Scientific Name Common Name(s) Koch’s Postulates 

Reference

Abies grandis§ Grand fir LeBoldus et al., 2018

Abies magnifica§ Red fir Chastagner and Riley, 2010

Acer circinatum§ Vine maple DiLeo et al., 2008

Acer macrophyllum* Bigleaf maple Garbelotto et al., 2003†

Acer pseudoplatanus Planetree maple COMTF, October 2006

Adiantum aleuticum* Western maidenhair fern Vettraino et al., 2006a

Adiantum jordanii* California maidenhair fern Vettraino et al., 2006a

Aesculus californica* California buckeye Garbelotto et al., 2003†

Aesculus hippocastanum Horse chestnut COMTF, October 2006

Arbutus menziesii* Madrone Garbelotto et al., 2003†

Arbutus unedo§ Strawberry tree Moralejo et al., 2008

Arctostaphylos columbiana§ Hairy manzanita DiLeo et al., 2008

Arctostaphylos glauca§ Bigberry manzanita Rooney-Latham et al., 2020

Arctostaphylos hooveri§ Santa Lucia manzanita Garbelotto et al., 2020

Arctostaphylos manzanita* Manzanita DiLeo et al., 2008

Arctostaphylos montereyensis§ Monterey manzanita Garbelotto et al., 2020

Arctostaphylos morroensis§ Morro manzanita Garbelotto et al., 2020

Arctostaphylos pilosula§ La Panza manzanita Garbelotto et al., 2020

Arctostaphylos pumila§ Sandmat manzanita Garbelotto et al., 2020

Arctostaphylos silvicola§ Silverleaf manzanita Garbelotto et al., 2020

Arctostaphylos viridissima§ White haired manzanita Rooney-Latham et al., 2020

Berberis aquifolium§

(≡Mahonia aquifolium)

Oregon grape Elliott et al., 2021b

Calluna vulgaris* Scotch heather C Orlikowski and Szkuta, 

2004

Camellia spp.* Camellia - all species, hybrids 

and cultivars

Beales et al., 2004a

Castanea sativa* Sweet chestnut Denman et al., 2005b

Ceanothus thyrsiflorus§ Blue blossom Ceanothus DiLeo et al., 2008

Chamaecyparis lawsoniana§ Port Orford cedar Brasier and Webber, 2012

Chrysolepis chrysophylla§ Golden chinquapin Rooney-Latham et al., 2022

Cinnamomum camphora* Camphor tree Rooney-Latham et al., 2013

Corylus cornuta§ Beaked hazelnut DiLeo et al., 2008

Fagus sylvatica European beech Harris et al., 2021
Scientific Name Common Name(s) Koch’s Postulates 

Reference

Frangula californica*

(=Rhamnus californica)

California coffeeberry Garbelotto et al., 2003†

Frangula purshiana*

(=Rhamnus purshiana)

Cascara buckthorn Vettraino et al., 2006b

Fraxinus excelsior European ash COMTF, August 2005

Gaultheria procumbens* Eastern teaberry Osterbauer et al., 2014

Gaultheria shallon§ Salal Elliott et al., 2021b

Griselinia littoralis* Kapuka Giltrap et al., 2007

Hamamelis virginiana* Witch hazel Giltrap et al., 2004

Heteromeles arbutifolia* Toyon Garbelotto et al., 2003†

Kalmia spp.* Mountain laurel - all species, 

hybrids and cultivars

Tooley and Browning, 2009†

Larix × eurolepis§ Hybrid larch Harris and Webber, 2016†

Larix decidua§ European larch Harris et al., 2021†

Larix kaempferi§ Japanese larch Harris and Webber, 2016

Laurus nobilis* Sweet bay COMTF, September 2004

Lonicera hispidula* California honeysuckle Davidson et al., 2003†

Lophostemon confertus§ Brisbane box Blomquist et al., 2020

Loropetalum chinense§ Chinese fringe flower Blomquist et al., 2012

Magnolia × loebneri§ Loebner magnolia Giltrap et al., 2007

Magnolia doltsopa*

(≡Michelia doltsopa)

Sweet michelia COMTF, October 2006

Magnolia stellata§ Star magnolia Giltrap et al., 2007

Maianthemum racemosum*

(=Smilacina racemosa)

False Solomon's seal Hüberli et al., 2005

Notholithocarpus densiflorus

(=Lithocarpus densiflorus)*

Tanoak Hansen et al., 2005

Parrotia persica* Persian ironwood Hughes et al., 2006

Phoradendron serotinum 

subsp. Macrophyllum§

Big-leaf mistletoe Riley and Chastagner, 2011

Photinia × fraseri* Red tip photinia Orlikowski and Szkuta, 

2004‡

Pieris spp.* Andromeda, Pieris - all species, 

hybrids and cultivars

Parke et al., 2004

Prunus laurocerasus Cherry laurel Elliott et al., 2020

Pseudotsuga menziesii var.

menziesii*

Douglas fir LeBoldus et al., 2018

Quercus agrifolia Coast live oak Rizzo et al., 2002

Quercus cerris European turkey oak COMTF, August 2006

Quercus chrysolepis Canyon live oak Murphy and Rizzo, 2003

Quercus falcata Southern red oak Brasier et al., 2004b; 
Scientific Name Common Name(s) Koch’s Postulates 

Reference

Quercus ilex* Holly oak Denman et al., 2005a

Quercus kelloggii California black oak Garbelotto et al., 2003†

Quercus parvula var. shrevei Shreve’s oak Rizzo et al., 2002

Rhododendron spp.* Rhododendron (including 

azalea) – all species, hybrids and 

cultivars

Hansen et al., 2005

Rosa gymnocarpa* Wood rose Hüberli et al., 2004

Salix caprea* Goat willow COMTF, August 2006

Sequoia sempervirens* Coast redwood Maloney et al., 2002

Syringa vulgaris* Lilac Beales et al., 2004b

Taxus baccata* English yew Lane et al., 2004

Trientalis latifolia* Western starflower Hüberli et al., 2003†

Umbellularia californica* California bay laurel DiLeo et al., 2009

Vaccinium myrtillus§ Whortleberry Herrero et al., 2011

Vaccinium parvifolium§ Red huckleberry Elliott et al., 2021b

Vaccinium ovatum* Evergreen huckleberry Hansen et al., 2005

Viburnum spp.* Viburnum – all species, hybrids 

and cultivars

Parke et al., 2004

Vinca minor§ Periwinkle Elliott et al., 2021a

§New additions to the proven host list

*Unmanufactured wood and wood products, including firewood, logs, and lumber of species listed above 

are not regulated. See Federal Regulations, 7 CFR 301.92 - 301.92-2.

Plants Associated with Phytophthora ramorum

(These are regulated only as nursery stock.)

Scientific Name Common Name Reference

Abies alba§ Silver fir O'Hanlon et al., 2016

Abies concolor White fir COMTF, October 2005

Abies procera§ Noble fir O'Hanlon et al., 2016

Acer davidii Striped bark maple COMTF, 2006

Acer laevigatum Evergreen Maple USDA-APHIS, 2005

Alnus cordata Italian alder O'Hanlon et al., 2016

Arctostaphylos glandulosa§ Eastwood's manzanita Rooney-Latham et al., 2017

Arctostaphylos montaraensis§ Montara manzanita COMTF, April 2020; Rooney-Latham, 

Confirmed

Arctostaphylos pallida§ Pallid manzanita Swiecki and Bernhardt, 2017

Arctostaphylos peninsularis§ Peninsular manzanita COMTF, April 2020; Rooney-Latham, 

Confirmed

Arctostaphylos rainbowensis§ Rainbow manzanita COMTF, April 2020
Scientific Name Common Name Reference

Arctostaphylos uva-ursi Kinnikinnick, COMTF, February 2020

Arctostaphylos virgata§ Bolinas manzanita Rooney-Latham et al., 2017

Arctostaphylos viscida§ Whiteleaf manzanita COMTF, April 2020; Rooney-Latham, 

Confirmed 2022

Ardisia japonica Marlberry CFIA Confirmed Positive Plants, 2005

Berberis nervosa

(≡Mahonia nervosa)

Creeping Oregon grape COMTF, June 2010

Betula pendula Silver birch Webber et al., 2010

Calycanthus occidentalis Spicebush COMTF, July 2005

Castanopsis orthacantha Castanopsis COMTF, September 2006

Ceanothus oliganthus§ Hairy ceanothus Rosenthal et al, 2021

Cercis chinensis§ Chinese redbud COMTF, May 2008

Choisya ternata§ Mexican orange blossom APHIS Confirmed Positive Plants, 2013

Clintonia andrewsiana Andrew’s clintonia COMTF, August 2004

Cornus kousa × Cornus 

capitata

Norman Haddon 

dogwood

EPPO, 2013

Cornus capitata§ Bentham's cornel DEFRA, 2015

Cornus kousa§ Kousa dogwood APHIS Confirmed Positive Plants, 2012 

Corylopsis spicata§ Spike winter hazel COMTF, February 2008

Daphniphyllum glaucescens§ COMTF, March 2009

Distylium myricoides Myrtle-leafed 

Distylium

COMTF, September 2006

Drimys winteri Winter’s bark Brasier et al., 2004a

Dryopteris arguta California wood fern COMTF, August 2004

Eucalyptus haemastoma Scribbly gum COMTF, September 2006

Euonymus kiautschovicus Spreading euonymus COMTF, 2006

Fothergilla major§ Mountain witch alder DEFRA, 2015

Fraxinus latifolia Oregon ash COMTF, September 2005; 

Garrya elliptica§ Silk tassel bush COMTF, August 2007; 

Hamamelis × intermedia (H. 

mollis & H. japonica)

Hybrid witchhazel APHIS Confirmed Positive Plants, 2012; 

Hamamelis mollis Chinese witchhazel COMTF, February 2005

Hydrangea seemannii§ Seemann's hydrangea DEFRA, 2015

Ilex aquifolium§ European holly EPPO, 2013

Ilex cornuta Chinese holly APHIS Confirmed Positive Plants, 2009

Ilex latifolia§ Tarajo holly DEFRA, 2015

Ilex purpurea Oriental holly COMTF, September 2006

Illicium parviflorum Swamp star anise APHIS Confirmed Positive Plants, 2009

Larix occidentalis§ Western larch LeBoldus and Søndreli, 2019

Leucothoe axillaris Fetterbush, doghobble COMTF, April 2006
Scientific Name Common Name Reference

Leucothoe fontanesiana Highland doghobble O'Hanlon et al., 2016

Lithocarpus glaber§ Japanese oak DEFRA, 2015

Lonicera periclymenum Common honeysuckle Canadian Food Inspection Agency, 2022

Magnolia × soulangeana Saucer magnolia COMTF, February 2005

Magnolia × thompsoniana§ hybrid magnolia COMTF, April 2008

Magnolia acuminata§ Cucumber tree DEFRA, 2015

Magnolia cavaleriei§ CFIA Confirmed Positive Plants, 2006

Magnolia delavayi§ Delavay's magnolia DEFRA, 2015

Magnolia denudata Yulan magnolia EPPO, 2013

Magnolia denudata ×

salicifolia§

Magnolia EPPO, 2013

Magnolia ernestii

(=Michelia wilsonii)

Michelia COMTF, March 2006

Magnolia figo§

(=Michelia figo)

Banana shrub COMTF, May 2008

Magnolia foveolata§ EPPO, 2013

Magnolia grandiflora Southern magnolia COMTF, June 2006

Magnolia insignis

(≡Manglietia insignis)

Red lotus tree COMTF, September 2006

Magnolia kobus§ Kobus magnolia EPPO, 2013

Magnolia liliiflora§ Lily magnolia EPPO, 2013

Magnolia lotungensis

(≡Parakmeria lotungensis)

Eastern joy lotus tree COMTF, September 2006

Magnolia maudiae

(≡Michelia maudiae)

Smiling monkey forest 

tree

Sansford and Woodhall, 2007

Magnolia salicifolia§ Anise magnolia EPPO, 2013

Molinadendron sinaloense APHIS Confirmed Positive Plants, 2011

Nerium oleander Oleander O'Hanlon et al., 2016

Nothofagus obliqua Patagonian oak Brasier et al., 2004a

Osmanthus decorus 

(≡Phillyrea decora; =P. 

vilmoriniana)

Osmanthus COMTF, March 2006

Osmanthus delavayi Delavay tea olive COMTF, February 2007

Osmanthus fragrans sweet olive Grünwald et al., 2008

Osmanthus heterophyllus Holly olive Grünwald et al., 2008

Osmorhiza berteroi Sweet Cicely COMTF, September 2005

Physocarpus opulifolius§ Ninebark COMTF, February 2008

Picea sitchensis§ Sitka spruce LeBoldus and Søndreli, 2019

Pickeringia montana§ Chaparral pea Rooney-Latham et al., 2017

Pinus ponderosa§ Ponderosa Pine Rosenthal et al., 2021

Pittosporum undulatum Victorian box Hüberli et al., 2006
Scientific Name Common Name Reference

Polystichum munitum§ Western Swordfern APHIS Confirmed Positive Plants, 2022

Prunus lusitanica Portuguese laurel 

cherry 

O'Hanlon et al., 2016

Pyracantha koidzumii Formosa firethorn Briere et al., 2005

Quercus acuta Japanese evergreen oak EPPO, 2013

Quercus petraea Sessile oak COMTF, September 2005

Quercus phillyraeoides§ Ubame oak O'Hanlon et al., 2016

Quercus robur§ English oak DEFRA, 2015

Quercus rubra Northern red oak EPPO, 2013

Ribes laurifolium§ Evergreen Flowering 

Currant

EPPO, 2013

Rosa (specific cultivars)

Royal Bonica (“MEImodac”) 

Pink Meidiland (“MEIpoque”) 

Pink Sevillana (“MEIgeroka”)

Royal Bonica rose

Pink Meidiland rose

Pink La Sevillana rose

EPPO, 2013; 

Rosa hybrida ‘Radrazz’§ Knock Out rose APHIS Confirmed Positive Plants, 2019

Rosa rugosa Rugosa rose COMTF, March 2006

Rubus spectabilis Salmonberry Hansen et al., 2005

Rubus ursinus§ California blackberry Rooney-Latham et al., 2017

Salix babylonica Weeping willow Canadian Food Inspection Agency 2007, 

Sarcococca hookeriana§ Himalayan sweet box Schlenzig et al., 2015

Schima argentea§ Brown and Brasier, 2007

Schima wallichii Chinese guger tree COMTF, February 2007

Sorbus aucuparia§ European mountain ash DEFRA, 2015

Syringa meyeri§ Meyer lilac APHIS Confirmed Positive Plants, 2019

Syringa pubescens§ Lilac APHIS Confirmed Positive Plants, 2019

Taxus × media Anglo-Japanese yew De Gruyter and Steeghs, 2006

Taxus brevifolia Pacific yew COMTF, September 2005

Torreya californica California nutmeg COMTF, September 2005

Toxicodendron diversilobum Poison oak Hansen et al., 2005

Trachelospermum 

jasminoides

Star jasmine Osterbauer et al., 2011

Tsuga heterophylla§ Western hemlock LeBoldus and Søndreli, 2019

Vaccinium intermedium§ DEFRA, 2015

Vaccinium vitis-idaea§ Lingonberry EPPO, 2013

Vancouveria planipetala Redwood ivy COMTF, September 2005

Veronica spicata 

(=Pseudolysimachion 

spicatum)

Spiked speedwell APHIS Confirmed Positive Plants, 2010

 §New additions to the associated plant list
Rationale for Lists:

Host Plants Regulated for P. ramorum:

Naturally infected associated plants are deemed host plants regulated for P. ramorum upon 

completion, documentation, review, and acceptance of traditional Koch’s postulates. 

Plants Associated with P. ramorum:

Plants associated with P. ramorum are naturally infected plants from which P. ramorum has been 

cultured and/or detected using polymerase chain reaction (PCR). Traditional Koch’s postulates 

have not yet been completed nor documented and reviewed for each of these associated plants.

These reports must be documented and reviewed by PPQ before they are listed as host plants.

Regulation at the genus level:

Plants included in either of the above lists may be regulated at the genus level. This will ensure 

appropriate and effective inspection in quarantine areas, regulated nurseries, and regulated 

articles to mitigate the spread of P. ramorum. Examples of this include when the number of 

individual species, hybrids, or cultivars listed or to be listed are determined to hinder appropriate 

and effective inspection or regulation; or when sufficient numbers of member species of a genus 

are known susceptible to the disease-causing organism, all members of that genus have a 

demonstrable risk of spreading that disease. Thus, to prevent the spread of disease, all members 

of that genus will be treated the same.

Agency Contact: 

William Wesela

National Policy Manager 

301-851-2229

Betsy Randall-Schadel

National Operations Manager 

919-855-7544

References

Beales, P., T. Brokenshire, A. Barnes, V. Barton, and K. Hughes. 2004a. First report of ramorum leaf 

blight and dieback (Phytophthora ramorum) on Camellia spp. in the UK. Plant Pathology 

53(4).

Beales, P., A. Schlenzig, and A. Inman. 2004b. First report of ramorum bud and leaf blight 

(Phytophthora ramorum) on Syringa vulgaris in the UK. Plant Pathology 53(4).

Blomquist, C., S. Rooney-Latham, M. Soriano, and J. McCarty. 2012. First Report of Phytophthora 

ramorum Causing a Leafspot on Loropetalum chinense, Chinese Fringe Flower in California. 

Plant Disease 96(12):1829-1829.

Blomquist, C. L., S. Rooney-Latham, M. C. Soriano, J. Ochoa, and D. Zwart. 2020. First detection of 

leaf blight and stem canker caused by Phytophthora ramorum on Brisbane box in the United 

States. Plant Disease (ja).

Brasier, C., S. Denman, A. Brown, and J. Webber. 2004a. Sudden oak death (Phytophthora 

ramorum) discovered on trees in Europe. Mycological Research 108(10):1108-1110.
Brasier, C., S. Denman, J. Rose, S. Kirk, K. Hughes, R. Griffin, C. Lane, A. Inman, and J. Webber. 

2004b. First report of ramorum bleeding canker on Quercus falcata, caused by Phytophthora 

ramorum. Plant Pathology 53(6):804-804.

Brasier, C., and J. Webber. 2012. Natural stem infection of Lawson cypress (Chamaecyparis 

lawsoniana) caused by Phytophthora ramorum. New Disease Reports 25.

Briere, S. C., S. Llewellyn, and G. Kristjansson. 2005. First report of Pyracantha koidzumii as a new 

host for Sudden Oak Death caused by Phytophthora ramorum.Sudden Oak Death Science 

Symposium II, Monterey, California.

Brown, A., and C. Brasier. 2007. Colonization of tree xylem by Phytophthora ramorum, P. kernoviae

and other Phytophthora species. Plant Pathology 56(2):227-241.

Canadian Food Inspection Agency, C.

Chastagner, G. A., and K. L. Riley. 2010. First Report of Phytophthora ramorum Infecting California 

Red Fir in California. Plant Disease 94(9):1170-1170.

COMTF. 2006. California Oak Mortality Task Force (COMTF) 2006 Sudden Oak Death & 

Phytophthora ramorum Summary Report, http://www.suddenoakdeath.org/library/newsletterarchive/.

COMTF. April 2006. California Oak Mortality Task Force (COMTF) Report, 

http://www.suddenoakdeath.org/library/newsletter-archive/.

COMTF. April 2008. California Oak Mortality Task Force (COMTF) Report, 

http://www.suddenoakdeath.org/library/newsletter-archive/.

COMTF. April 2020. California Oak Mortality Task Force (COMTF) Report, 

http://www.suddenoakdeath.org/library/newsletter-archive/.

COMTF. August 2004. California Oak Mortality Task Force (COMTF) Report, 

http://www.suddenoakdeath.org/library/newsletter-archive/.

COMTF. August 2005. California Oak Mortality Task Force (COMTF) Report, 

http://www.suddenoakdeath.org/library/newsletter-archive/.

COMTF. August 2006. California Oak Mortality Task Force (COMTF) Report, 

http://www.suddenoakdeath.org/library/newsletter-archive/.

COMTF. August 2007. California Oak Mortality Task Force (COMTF) Report, 

http://www.suddenoakdeath.org/library/newsletter-archive/.

COMTF. February 2005. California Oak Mortality Task Force (COMTF) Report, 

http://www.suddenoakdeath.org/library/newsletter-archive/.

COMTF. February 2007. California Oak Mortality Task Force (COMTF) Report, 

http://www.suddenoakdeath.org/library/newsletter-archive/.

COMTF. February 2008. California Oak Mortality Task Force (COMTF) Report, 

http://www.suddenoakdeath.org/library/newsletter-archive/.

COMTF. February 2020. California Oak Mortality Task Force (COMTF) Report, 

http://www.suddenoakdeath.org/library/newsletter-archive/.

COMTF. July 2005. California Oak Mortality Task Force (COMTF) Report, 

http://www.suddenoakdeath.org/library/newsletter-archive/.

COMTF. June 2006. California Oak Mortality Task Force (COMTF) Report, 

http://www.suddenoakdeath.org/library/newsletter-archive/.

COMTF. June 2010. California Oak Mortality Task Force (COMTF) Report, 

http://www.suddenoakdeath.org/library/newsletter-archive/.

COMTF. March 2006. California Oak Mortality Task Force (COMTF) Report, 

http://www.suddenoakdeath.org/library/newsletter-archive/.

COMTF. March 2009. California Oak Mortality Task Force (COMTF) Report, 

http://www.suddenoakdeath.org/library/newsletter-archive/.
COMTF. May 2008. California Oak Mortality Task Force (COMTF) Report, 

http://www.suddenoakdeath.org/library/newsletter-archive/.

COMTF. October 2005. California Oak Mortality Task Force (COMTF) Report, 

http://www.suddenoakdeath.org/library/newsletter-archive/.

COMTF. October 2006. California Oak Mortality Task Force (COMTF) Report, 

http://www.suddenoakdeath.org/library/newsletter-archive/.

COMTF. September 2004. California Oak Mortality Task Force (COMTF) Report, 

http://www.suddenoakdeath.org/library/newsletter-archive/.

COMTF. September 2005. California Oak Mortality Task Force (COMTF) Report, 

http://www.suddenoakdeath.org/library/newsletter-archive/.

COMTF. September 2006. California Oak Mortality Task Force (COMTF) Report, 

http://www.suddenoakdeath.org/library/newsletter-archive/.

Davidson, J., S. Werres, M. Garbelotto, E. Hansen, and D. Rizzo. 2003. Sudden oak death and 

associated diseases caused by Phytophthora ramorum. Plant Health Progress 4(1):12.

De Gruyter, J., and M. H. C. G. Steeghs. 2006. Managing Phytophthora ramorum in the Netherlands. 

EPPO Bulletin 36(2):399-401.

DEFRA. 2015. Fera list of natural hosts for Phytophthora ramorum with symptom and location. 

Department for Environment Food & Rural Affairs (DEFRA).

Denman, S., S. Kirk, C. Brasier, V. Barton, K. Hughes, and J. Webber. 2005a. Phytophthora 

ramorum on Quercus ilex in the United Kingdom. Plant Disease 89(11):1241-1241.

Denman, S., S. Kirk, C. Brasier, K. Hughes, R. Griffin, E. Hobdon, and J. Webber. 2005b. Foliar 

infection of sweet chestnut (Castanea sativa) by Phytophthora ramorum in the UK. Plant 

Pathology 54(4).

DiLeo, M., R. Bostock, and D. Rizzo. 2009. Phytophthora ramorum does not cause physiologically 

significant systemic injury to California bay laurel, its primary reservoir host. Phytopathology 

99(11):1307-1311.

DiLeo, M. V., J. C. Bienapfl, and D. M. Rizzo. 2008. Phytophthora ramorum Infects Hazelnut, Vine 

Maple, Blue Blossom, and Manzanita Species in California. Plant Health Progress 9(1):50.

Elliott, M., L. Rollins, T. Bourret, and G. Chastagner. 2020. First report of leaf blight caused by 

Phytophthora ramorum on cherry laurel (Prunus laurocerasus) in Washington State, USA. 

Plant Disease (ja).

Elliott, M., L. Rollins, T. Bourret, and G. Chastagner. 2021a. First report of leaf blight caused by 

Phytophthora ramorum on periwinkle (Vinca minor) in Washington State, USA. Plant 

Disease (ja).

Elliott, M., L. Rollins, T. Bourret, J. Hulbert, and G. Chastagner. 2021b. Three New Hosts for 

Phytophthora ramorum Confirmed in Washington State: Salal, Oregon Grape, and Red 

Huckleberry. Plant Health Progress Pre-print(https://doi.org/10.1094/PHP-01-21-0003-FI).

EPPO. 2013. Pest risk management for Phytophthora kernoviae and Phytophthora ramorum. (13-

18716). European and Mediterranean Plant Protection Organization (EPPO), Paris, France. 60 

pp.

Garbelotto, M., J. Davidson, K. Ivors, P. Maloney, D. Hüberli, S. t. Koike, and D. Rizzo. 2003. Nonoak native plants are main hosts for sudden oak death pathogen in California. California 

Agriculture 57(1):18-23.

Garbelotto, M., T. Popenuck, B. Hall, w. schweigkofler, F. Dovana, R. Goldstein De Salazar, D. 

Schmidt, and L. Sims. 2020. Citizen science uncovers Phytophthora ramorum as a threat to 

several rare or endangered California manzanita species. Plant Disease (ja).

Giltrap, P., K. Hughes, V. Barton, E. Hobden, P. Barber, and K. Izzard. 2007. Phytophthora ramorum

on three new hosts detected using on-site diagnostics. Plant Pathology 56(4).
Giltrap, P., A. Inman, V. Barton, A. Barnes, C. Lane, K. Hughes, J. Tomlinson, M. Dean, and K. 

Izzard. 2004. First report of ramorum dieback (Phytophthora ramorum) on Hamamelis 

virginiana in the UK. Plant Pathology 53(4).

Grünwald, N., E. Goss, M. Larsen, C. Press, V. McDonald, C. Blomquist, and S. Thomas. 2008. First 

report of the European lineage of Phytophthora ramorum on Viburnum and Osmanthus spp. 

in a California nursery. Plant Disease 92(2):314-314.

Hansen, E., J. Parke, and W. Sutton. 2005. Susceptibility of Oregon forest trees and shrubs to 

Phytophthora ramorum: a comparison of artificial inoculation and natural infection. Plant 

Disease 89(1):63-70.

Harris, A. R., C. M. Brasier, B. Scanu, and J. F. Webber. 2021. Fitness characteristics of the 

European lineages of Phytophthora ramorum. Plant Pathology 70(2):275-286.

Harris, A. R., and J. F. Webber. 2016. Sporulation potential, symptom expression and detection of 

Phytophthora ramorum on larch needles and other foliar hosts. Plant Pathology 65(9):1441-

1451.

Herrero, M., B. Toppe, and M. Brurberg. 2011. First Report of Phytophthora ramorum Causing 

Shoot Dieback on Bilberry (Vaccinium myrtillus) in Norway. Plant Disease 95(3):355-355.

Hüberli, D., K. Ivors, A. Smith, J. Tse, and M. Garbelotto. 2005. First report of foliar infection of 

Maianthemum racemosum by Phytophthora ramorum. Plant Disease 89(2):204-204.

Hüberli, D., K. Reuther, A. Smith, S. Swain, J. Tse, and M. Garbelotto. 2004. First report of foliar 

infection of Rosa gymnocarpa by Phytophthora ramorum. Plant Disease 88(4):430-430.

Hüberli, D., W. Van Sant-Glass, J. Tse, and M. Garbelotto. 2003. First report of foliar infection of 

starflower by Phytophthora ramorum. Plant Disease 87(5):599-599.

Hüberli, D., C. Wilkinson, M. Smith, M. Meshriy, T. Harnik, and M. Garbelotto. 2006. Pittosporum 

undulatum is a potential Australian host of Phytophthora ramorum. Australasian Plant 

Disease Notes 1(1):19-21.

Hughes, K., P. Giltrap, V. Barton, E. Hobden, J. Tomlinson, and P. Barber. 2006. On-site real-time 

PCR detection of Phytophthora ramorum causing dieback of Parrotia persica in the UK. 

Plant Pathology 55(6):813.

Lane, C., P. Beales, K. Hughes, J. Tomlinson, A. Inman, and K. Warwick. 2004. First report of 

ramorum dieback (Phytophthora ramorum) on container‐grown English yew (Taxus baccata) 

in England. Plant Pathology 53(4):522-522.

LeBoldus, J., K. Sondreli, W. Sutton, P. Reeser, S. Navarro, A. Kanaskie, and N. Grünwald. 2018. 

First report of Phytophthora ramorum lineage EU1 infecting Douglas fir and Grand fir in 

Oregon. Plant Disease 102(2):455-455.

LeBoldus, J. M., and K. L. Søndreli. 2019. Comparative Epidemiology of EU1 and NA1 Lineages of 

Phytophthora ramorum in Southwestern Oregon Tanoak forests.The Seventh Sudden Oak 

Death Science Symposium, San Francisco, CA.

Maloney, P., D. Rizzo, S. Koike, T. Harnik, and M. Garbelotto. 2002. First report of Phytophthora 

ramorum on coast redwood in California. Plant Disease 86(11):1274-1274.

Moralejo, E., L. Belbahri, G. Calmin, J. García‐Muñoz, F. Lefort, and E. Descals. 2008. Strawberry 

tree blight in Spain, a new disease caused by various Phytophthora species. Journal of 

phytopathology 156(10):577-587.

Murphy, S., and D. Rizzo. 2003. First report of Phytophthora ramorum on canyon live oak in 

California. Plant Disease 87(3):315-315.

O'Hanlon, R., J. Choiseul, M. Corrigan, T. Catarame, and M. Destefanis. 2016. Diversity and 

detections of Phytophthora species from trade and non‐trade environments in Ireland. EPPO 

Bulletin 46(3):594-602.

Orlikowski, L., and G. Szkuta. 2004. First notice of Phytophthora ramorum on Calluna vulgaris, 
Photinia fraseri and Pieris japonica in Polish container-ornamental nurseries. 

Phytopathologia Polonica 34:87-92.

Osterbauer, N., A. Trippe, S. Lane, and S. Lewis. 2011. First report of Phytophthora ramorum

infecting Trachelospermum jasminoides in Oregon. Phytopathology 101(6).

Osterbauer, N. K., S. Lane, and A. Trippe. 2014. Phytophthora ramorum identified infecting eastern 

teaberry (Gaultheria procumbens) plants shipped to Oregon. Plant Health Progress 15(1).

Parke, J., R. Linderman, N. Osterbauer, and J. Griesbach. 2004. Detection of Phytophthora ramorum

blight in Oregon nurseries and completion of Koch's postulates on Pieris, Rhododendron, 

Viburnum, and Camellia. Plant Disease 88(1):87-87.

Riley, K. L., and G. A. Chastagner. 2011. First report of Phytophthora ramorum infecting mistletoe 

in California. Plant Health Progress (February).

Rizzo, D., M. Garbelotto, J. Davidson, G. Slaughter, and S. Koike. 2002. Phytophthora ramorum as 

the cause of extensive mortality of Quercus spp. and Lithocarpus densiflorus in California. 

Plant Disease 86(3):205-214.

Rooney-Latham, S., C. Blomquist, A. Williams, E. Gunnison, and T. Pastalka. 2017. Identification of 

five new hosts of Phytophthora ramorum in an infested forest in California. Pages 83-84 in 

Proceedings of the sudden oak death sixth science symposium. Gen. Tech. Rep. GTR-PSW255., Albany, CA.

Rooney-Latham, S., C. L. Blomquist, M. C. Soriano, and T. Pastalka. 2022. First Report of Dieback 

Caused by Phytophthora ramorum on Golden Chinquapin, Chrysolepis chrysophylla, in 

California. Plant Disease 0(ja):null.

Rooney-Latham, S., C. L. Blomquist, M. C. Soriano, and M. Uhler. 2020. First Report of 

Phytophthora ramorum causing foliar and stem blight of two California native Arctostaphylos

species, A. viridissima and A. glauca. Plant Disease (ja).

Rooney-Latham, S., E. Honeycutt, J. Ochoa, N. J. Grunwald, and C. L. Blomquist. 2013. First Report 

of Camphor Tree (Cinnamomum camphora) as a Host of Phytophthora ramorum. Plant 

Disease 97(10):1377-1378.

Rooney-Latham, S. C. D. o. F. a. A. C. Confirmed 2022.

Sansford, C. E., and J. Woodhall. 2007. Datasheet for Phytophthora ramorum. Central Science 

Laboratory (CSL) Forest Research. PPP 11824 and PPP 12421 pp.

Schlenzig, A., R. Campbell, and J. Chard. 2015. Phytophthora species infecting hardy ornamentals in 

nurseries and the managed environment in Scotland. Journal of phytopathology 163(7-8):686-

689.

Swiecki, T. J., and E. A. Bernhardt. 2017. Phytophthora cinnamomi diagnostic testing in pallid 

manzanita populations. Phytosphere Research, Vacaville, CA. 48 pp.

Tooley, P. W., and M. Browning. 2009. Susceptibility to Phytophthora ramorum and inoculum 

production potential of some common eastern forest understory plant species. Plant Disease 

93(3):249-256.

USDA-APHIS. 2005. Revision of Associated Regulated Articles (nursery stock); Additions to 

APHIS List of Hosts and Plants Associated with P. ramorum. September 14, 2005. (DA2005-28). United States Department of Agriculture (USDA), Animal and Plant Health 

Inspection Service (APHIS), https://nationalplantboard.org/laws-and-regulations-spro-lettersarchived-phytophthora-ramorum-spro-letters/.

Vettraino, A., D. Hüberli, S. Swain, J. Bienapfl, A. Smith, and M. Garbelotto. 2006a. First report of 

infection of Maiden-Hair Fern (Adiantum jordanii and A. aleuticum) by Phytophthora 

ramorum in California. Plant Disease 90(3):379-379.

Vettraino, A., D. Hüberli, S. Swain, A. Smith, and M. Garbelotto. 2006b. A new report of 

Phytophthora ramorum on Rhamnus purshiana in Northern California. Plant Disease 
90(2):246-246.

Webber, J., M. Mullett, and C. Brasier. 2010. Dieback and mortality of plantation Japanese larch 

(Larix kaempferi) associated with infection by Phytophthora ramorum. New Disease Reports 

22(19):2044-0588.2010.